What is a network patch panel?

1.  What is a network patch panel?

What is a network patch panel? Many people have come into contact with network patch panels, but even manufacturers who produce them may not know how to define them. So what exactly is a network patch panel?

According to ISO/IEC 11801:2002, a network patch panel is a wiring device suitable for patch cords connections. It facilitates the movement and changes of the cabling system, making it more convenient.

According to ANSI/TIA 568-B, a network patch panel is a cross-connect system consisting of conveniently managed pairs of connectors.

ISO/IEC 11801：2002

The cover of ANSI/TIA 568B

Based on the above, we can conclude that a network patch panel is a centralized and conveniently managed wiring device consisting of paired connectors. It uses patch cords for cross-connections and is used for connecting vertical subsystems, horizontal subsystems, or the termination points of user information. It also allows for centralized management, distribution, and adjustment of the cabling systems.

2.  History of network patch panels.

According to information from Wikipedia: Structured cabling evolved from voice systems. Since the invention of the telephone by Bell in 1875, wired instant communication without the need for translators gradually emerged. Although the telegraph invented by John Cooke in 1836 also enabled instant communication, it required translating the text into Morse code before sending, which was more cumbersome. Therefore, after the invention of the telephone, telephone exchanges were established worldwide. After World War II, telephones began to enter ordinary households from telephone exchanges. Along with the rise of smart buildings in the United States and the increasing number of telephone installations in every household, as well as various other wiring systems, the number of systems in buildings increased. Traditional independent wiring systems could no longer meet the needs of safety, comfort, convenience, etc. Therefore, in the late 1980s, AT&T introduced the structured cabling system (SCS) and launched the 110 patch panel. In the 1990s, companies such as Schneider Electric improved the original 110 patch panel by replacing punch-down blocks with IDC punch-down blocks and adding RJ45 sockets at the front end, leading to the development of network patch panels. Through their unremitting efforts, network patch panels were eventually recognized by the Telecommunications Industry Association (TIA) and the International Electrotechnical Commission (IEC). They were included in the ANSI/TIA 568B Commercial Building Telecommunications Cabling Standard published in 2001 and the ISO/IEC 11801:2002 Generic Cabling for Customer Premises standard published in 2003.

BELL invented the telephone

 110 patch panels

RJ45 Module Port

Afterward, patch panels began to flourish. Currently, various types of patch panel products have been developed, including integrated patch panels, modular patch panels, angled patch panels, electronic patch panels, and so on. These patch panels can be categorized based on their transmission performance, such as Category 5e patch panels, Category 6 patch panels, Category 6A patch panels, etc. They can also be classified as shielded patch panels or unshielded patch panels based on the presence of shielding. We will explain the advantages and disadvantages of various patch panels later.

3.  The basic structure and materials of patch panels:

Currently, the patch panels available on the market are generally 24-port patch panels with a length of 19 inches (482.6mm ± 0.5mm) and a height of 1U (44.4 ± 0.1). They are typically black in color.

The front housing of the patch panel is generally made of ABS plastic. According to information from Wikipedia, ABS plastic has excellent impact resistance, which can withstand the impacts that the patch panel may encounter during installation and its 15-year lifespan. ABS plastic exhibits excellent high and low-temperature resistance, ranging from -40°C to 93°C, which meets the requirements of most regions where patch panels are used (-20°C to 70°C). In addition, ABS resin is insoluble in common solvents in daily life, ensuring that the patch panel is not easily corroded during use. It has a good surface gloss, making it easy to color and undergo secondary processing such as electrostatic spraying, allowing for the production of patch panel housings in various colors to meet different needs. Furthermore, ABS resin has excellent insulation performance, which is not significantly affected by temperature, humidity, or frequency, ensuring that the links do not short-circuit and that signals are effectively transmitted. In summary, ABS resin is a widely used synthetic resin in patch panels.

The front structure of the patch panel mainly consists of RJ45 sockets and an identification area. The identification area is composed of paper identification strips and PE plastic partitions. The RJ45 sockets are used for connecting network patch cords, and the sockets are equipped with eight "pins." The eight pins are generally arranged in an interleaved manner, which helps to separate electrical signals as much as possible and reduce interference that may occur during the use of the patch panel.

The main material of the "pins" is phosphor bronze. Phosphor bronze is a copper alloy that adds phosphorus to pure copper-tin bronze to achieve wear resistance. Phosphor bronze has strong wear resistance, which can meet the requirements of plug-and-play testing for information sockets of over 750 times. It also has impact resistance and does not produce sparks during impact, which can meet the requirements for plugging and unplugging PoE patch cords. Additionally, phosphor bronze has a maximum operating temperature of 250°C, meeting the usage requirements of the patch panel ranging from -20°C to 70°C. Therefore, phosphor bronze is widely used in the sockets of patch panels for mobile phones, computers, and interactive devices.

However, phosphor bronze is a copper alloy that is prone to oxidation in the air. Therefore, manufacturers of patch panels employ a process of nickel plating the phosphor bronze to prevent further oxidation. Nickel, when in contact with moisture and air, forms a dense oxide film that prevents the underlying material from further oxidation. The oxidation and rusting of copper alloys increase the DC loop resistance and unbalanced resistance, leading to increased insertion loss and return loss. By nickel plating the surface of phosphor bronze, problems such as data packet loss and transmission link failures caused by rust can be solved.

Finished patch cords in patch panels, especially in patch panels that require frequent adjustment of information points or reconfiguration, often cause certain wear on the "pins" due to frequent plugging and unplugging of patch cables. In order to meet the 15-year design requirements, it is necessary to coat the "pins" with wear-resistant materials to provide durability. To achieve the desired wear resistance, manufacturers of patch panels generally use gold plating on the "pins". Information jacks that are gold plated can withstand plug-and-unplug tests of 750 times or more, as required by the industry.

The framework of the patch panel is made of cold-rolled steel, which has excellent mechanical strength and can withstand various extrusions and impacts. It is not easily deformed, and the cold-rolled steel plate is resistant to rust, meeting the minimum 15-year usage requirements for network patch panels.

The rear end of the patch panel consists of IDC termination blocks and a rear cover. The rear cover is made of ABS plastic. The cover is labeled with TIA 568A/B wiring schemes and color codes for wire cores.

The housing of the IDC termination block is made of PC plastic, also known as polycarbonate plastic. It is a plastic with excellent elasticity and impact resistance, able to quickly recover its original shape after being compressed or deformed. Therefore, IDC termination blocks made of PC plastic not only withstand the impact of termination tools without damage but also quickly recover their position and clamp the cables, preventing them from coming loose.

The core of the termination block is nickel-plated phosphor bronze IDC pins. The upper part is used to clamp and break the insulation of wire cores and make contact with the conductors inside the wire cores, transmitting signals to the circuit board. The lower part is soldered to the circuit board.

The interior of the patch panel consists of circuit boards. In integrated patch panels, six information jacks share one circuit board, while in modular patch panels, each information jack has its own circuit board. The circuit boards of different brands of patch panels are generally different because comprehensive cabling manufacturers of different brands have variations in cable twisting pitches. The design of the patch panel's circuit board is based on the cable's structural scheme. Therefore, the circuit boards of patch panels from different manufacturers are generally different.

4. Quality requirements for patch panels.

Patch panels generally undergo plug-and-unplug tests on information jacks, with the industry typically requiring information jacks to pass at least 750 plug-and-unplug tests. Regarding transmission performance, patch panels are generally used in conjunction with cables and cannot be used independently. Therefore, there are no individual tests specifically for patch panels. Generally, their transmission performance is tested through permanent link testing or channel testing using equipment such as FLUKE testers.

Furthermore, due to the increasing awareness of environmental protection in recent years, the plastic materials used in patch panels must meet the environmental testing requirements of ROHS or REACH and other EU standards.

5. Common Network Patch Panels, their advantages and disadvantages

5.1 Currently, the most common types of network patch panels on the market are integrated patch panels, modular patch panels, angled patch panels, and electronic patch panels. Among them, integrated patch panels are the most prevalent.

 

Integrated Patch Panels, as seen from the appearance, have 24 RJ45 jacks encapsulated within the framework of the patch panel, forming a unified unit. The internal structure generally consists of six RJ45 jacks sharing one circuit board. The advantages of this type of patch panel lie in its mature production process and low production cost, making it relatively inexpensive compared to other types of patch panels. Additionally, the construction process is simple, as installers only need to mount the cables onto the patch panel. As a result, it is favored by structured cabling installers. However, due to the integrated encapsulation and the structure where multiple information points share one circuit board, it becomes challenging to replace a damaged port. Therefore, once a port is damaged, it is generally necessary to abandon that port. Moreover, installers can only purchase pre-installed 24-port network patch panels from manufacturers, without the ability to modify the ports according to their actual needs or mix different types of ports. It is relatively inflexible. In terms of transmission performance, the sharing of one circuit board among six information jacks increases mutual interference between different information points, reducing the external near-end crosstalk power sum attenuation (PS ANEXT) and weakening the ability to resist external interference.

Considering the inability to replace damaged ports and the inflexibility of port replacement in integrated network patch panels, comprehensive cabling manufacturers have conducted extensive research and improvement, resulting in the introduction of modular patch panels. As the name suggests, modular patch panels encapsulate each RJ45 information jack independently and assemble them together within the patch panel's framework. The advantage of this structure is that each information jack has its own dedicated circuit board and is encapsulated in an independent space using PC material. From a transmission performance perspective, the modular patch panel ensures the independent operation of each information jack, minimizing interference between information systems connected to the modular patch panel. This enhances the system's ability to resist external interference. Furthermore, due to the use of an independent structure, users can customize the RJ45 ports according to their specific design requirements, including reducing the number of ports or incorporating other types of RJ45 or even RJ11 interfaces. Therefore, modular patch panels offer greater flexibility and compatibility compared to integrated patch panels, while also reducing unnecessary waste and saving installation space.

In addition, due to the use of a modular independent design, each RJ45 information module on the patch panel can be removed and reinstalled during construction. When installing patch panels in wall-mounted or embedded cabinets, the installation environment is elevated, and installers must use a "step ladder" to perform cabling, which can be challenging due to the limited working space. While it is possible to use integrated patch panels for construction by installing them upside down, the operational space is small, and it can easily lead to wiring failures, making it less convenient to use for construction. With modular patch panels, installers can remove the information modules, complete the construction on the ground, and then reinstall them into the patch panel. Therefore, modular patch panels can meet more confined construction environments.

However, the disadvantage of modular patch panels is that, due to the use of an independent structure, they require more production materials and a more intricate production process, resulting in a higher price compared to integrated patch panels. Additionally, due to the smaller size of the labeling area resulting from the independent design of modular patch panels, it is more difficult for personnel who rely on labeling for wiring to work with modular patch panels compared to integrated patch panels. Furthermore, because modular patch panels are detachable, there is a small possibility that some construction workers may substitute inferior or counterfeit information modules on the patch panel frame, deceiving consumers.

In the early stages, both integrated and modular network patch panels were linear-type patch panels. Network patch panels must be used in conjunction with horizontal cable management racks to better manage patch cords and enhance the aesthetics of cabling environments. However, the design solution of network patch panels combined with cable management racks requires 2U of cabinet space, as cabinets typically have 42U.

42U cabinet

When there is sufficient cabinet space, using the structure of network patch panels combined with cable management racks is feasible. However, when cabinet space is limited, this structure will occupy too many cabinet resources. The shortcomings of this structure become increasingly prominent in today's era of rapid development of the Internet and increasingly scarce cabinet resources.

To address the issue of excessive cabinet resource usage caused by linear-type patch panels combined with cable management racks, comprehensive cabling manufacturers have introduced a new type of network patch panel called the angled patch panel. This patch panel divides the information ports that were originally arranged in a straight line into two parts by breaking them in the middle. A rotating screw is installed at the center of the connection, allowing users to rotate the patch panel on the Z-axis from 0 to 120 degrees according to their needs. Using this patch panel not only isolates some crosstalk between cables but also automatically separates the cables into two parts, enabling stepped cable management. Users only need to wire based on the length of their information ports and directly connect the patch cords to the next RJ45 port without the need for a cable management rack. This can save 1U of cabinet space.

Angled Patch Panels

The drawback of angled patch panels is that their structure is more complex compared to modular patch panels and integrated patch panels. As a result, their production process is more intricate, requiring more production materials, which leads to a higher price.

Furthermore, angled patch panels have certain requirements for the installation cabinet. Generally, a cabinet with a depth of 800mm is required to accommodate angled patch panels, and using these patch panels in a regular cabinet may result in the cabinet door not being able to close properly.

Traditional patch panels typically have labeling strips installed at the port to facilitate network administrators in managing different information points. However, these labeling strips are prone to lose, and the identification codes become increasingly blurred over time, eventually losing their identification function. This poses a challenge for the later maintenance and management of the network. Therefore, in recent years, a new type of network patch panel called the electronic network patch panel has become popular. This patch panel replaces traditional paper labeling strips with electronic LCD screens. During construction, installers can input the port numbers into the display screen using a computer. Once the patch panel is powered on, it will display the corresponding port numbers, making it convenient for subsequent personnel to manage the network. Additionally, some electronic patch panels can also perform real-time power-over-Ethernet (PoE) consumption statistics and transmit the data of the corresponding ports to the network management personnel's devices through wireless LAN, facilitating efficient network management.

A cabinet with a depth of 800mm

The disadvantage of electronic patch panels is that the introduction of electronic LCD screens increases the complexity of production processes and production costs for network patch panels. Additionally, powering the electronic patch panels leads to energy consumption and can introduce external interference to the cables. Moreover, if there are errors in data collection and display on the electronic patch panels, it may mislead network administrators.

5.2  In addition to the aforementioned network patch panels, they can also be classified based on transmission performance, such as Category 5e patch panels, Category 6 patch panels, and Category 6A patch panels. Let's introduce them one by one.

Category 5e network patch panels are used for Category 5e cabling systems. They have a transmission bandwidth of 155MHz and can support up to 1000Mbps Ethernet networks. They used to dominate the market for structured cabling but have gradually decreased in market share due to the development of the internet and the increasing demand for high-bandwidth networks.

Category 6 network patch panels are suitable for Category 6 cabling systems. They have a transmission bandwidth of 250MHz and can stably transmit 1Gbps Ethernet networks. They comply with the General Requirements for User Premises Cabling in Information Technology - Generic Cabling for Customer Premises (ISO/IEC 11801:2018), which specifies the use of Category 6 or higher cabling systems for horizontal cabling in buildings.

Category 6A network patch panels are used for Category 6A cabling systems. They have a transmission bandwidth of 500MHz and can stably transmit 10Gbps Ethernet networks. They are suitable for future smart building cabling applications.

5.3 Furthermore, patch panels can be classified as shielded or unshielded based on the presence of a metal shielding layer.

Shielded patch panels, with galvanized copper shells as the outer casing of the information modules, effectively shield against electromagnetic interference. They are suitable for government and military organizations with confidentiality requirements, as well as hospitals and factories with strong electromagnetic interference sources. However, shielded patch panels are generally more expensive and have higher construction requirements compared to unshielded patch panels. Therefore, they are not recommended for general scenarios.

Unshielded patch panels do not have a metal shielding layer, and the outer casing of the information modules is made of ABS plastic and PC plastic. They have poorer electromagnetic shielding effects and are suitable for general cabling environments. They are cheaper and the most commonly used patch panels in daily applications.

5.4 In addition, there are some other types of patch panels available on the market. Due to limited words, let me briefly introduce two types: feed-through patch panels and fiber optic patch panels.

Feed through patch panels

Fiber optic patch panels

Feed-through network patch panels are wiring racks with dual RJ45 jacks. When used, the cables are directly terminated with rj45 connectors and plugged in for use. The cables installed on one end of the network patch panel are single-strand twisted pair cables. During actual construction, the rj45 connectors are directly attached to the single-strand twisted pair cables for use. The tension on the single-strand twisted pair cables is significant, which can easily cause poor contact or even damage to the connectors and information jacks on the patch panel, resulting in a faulty cable link.

Fiber optic network patch panels generally have plastic fibers installed on the patch panel and are used in conjunction with fiber optic cables. They can achieve the purpose of quick cable identification within a second. However, according to the requirements of the Comprehensive Cabling System Engineering Design Specification (GB 50311), the expected service life of a permanent link is generally 15 years. A properly constructed cabling system that meets industry standards and specifications should not encounter quality issues during normal use. Therefore, this design is somewhat impractical.

Until now, we have covered the basic introduction to the common types of network patch panels available in the market.

6.  Network patch panel solutions

A typical network patch panel has 24 ports. When estimating project budgets, you can use a single network patch panel to manage information points on one or even multiple floors, based on the actual requirements.

A 24-port network patch panel is generally used in conjunction with a 12-ring horizontal cable manager, which is 19 inches long and 1U high. Normally, two patch cords are installed in each cable management ring, arranged in front and back. It is generally not recommended to install more than two patch cords to avoid overcrowding and affecting the transmission performance of the links.

It is recommended to design the solution by pairing shielded cabling products with shielded network patch panels, and unshielded cabling products with unshielded network patch panels. If a design scheme combines a shielded network patch panel with unshielded cables and patch cords, the shielded network patch panel will not provide shielding and its shielding functionality will be wasted. Similarly, using an unshielded network patch panel for a shielded link not only wastes the shielding capability of the link but also may result in inadequate shield grounding, which can lead to the cable being affected by induced currents from the shield and even indirect lightning strikes.